Abstract
Purpose :
Amnion-derived Multipotent Progenitor Cells secrete pro-healing cytokines and growth factors that promote migration of fibroblasts and keratinocytes. We studied the efficacy of the ST266 secretome in post-operative inflammation compared to balanced salt saline solution (BSS), and Durezol (Difluprednate 0.05%), a commercially available topical anti-inflammatory corticosteroid for ophthalmic use.
Methods :
On Day 0, 24 anesthetized NZW rabbits underwent a 2.7mm full thickness clear corneal incision in the superior nasal cornea of the left eye. Following the procedure, buprenorphine and neomycin/polymyxin B gramicidin were administered. The cornea was sutured using 8-0 vicryl. The right eye acted as a control and was not subjected to surgery or treatment. Rabbits were divided into four groups (n=6/group): group 1 - BSS 4x/day, group 2 - ST266 8x/day, group 3 - ST266 2x/day, and group 4 - 0.1% Durezol 4x/day. Eyes were analyzed at baseline, days 1, 2, 4, 7, 10, and 14. Endpoint parameters were Hackett-McDonald ocular irritation scoring, total redness, and histopathology.
Results :
Ocular irritation scoring results show that at 24 hours post-surgery, the BSS group had a score of 12.0 ± 0.6; the ST266 8x/day group had a score of 8.8 ± 1.3, the ST266 2x/day group had a score of 9.2 ± 0.8; and the Durezol group had a score of 5.8±1.3. This anti-inflammatory effect was maintained up to 10 days after surgery and reached the same irritation score as BSS at day 14. Conjunctiva redness/congestion and iris aqueous flare were also decreased when compared to control BSS treatment. Histopathology scoring also showed decreased inflammatory cell infiltration and fibrosis in both cornea and anterior segment sections when compared to control.
Conclusions :
Topical ocular treatment with ST266 resulted in lower ocular irritation scores and total redness compared to the control BSS group up to 14 days after surgery. Histopathology scores of cornea and anterior segment sections showed decreased neutrophil infiltration and fibrosis when compared to BSS control. No significant difference in inflammatory scores was observed between frequency of ST266 treatments. ST266 treatment was not as effective in reducing inflammation as topical steroid treatment in this model. Test article formulation and frequency of application were well-tolerated.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.